1. New early Palaeozoic trilobites of eastern Siberia and Kazakhstan;Kryskov,1960
2. Tchernysheva N Ye. Cambrian trilobites of the Family Oryctocephalidae. In: Problems of oil and gas occurrence in the Soviet Arctic, palaeontology and biostratigraphy. 3 Trudy nauchnoissledovatel’skii geologii Institut Arktiki (NIIGA) 1962; 127, Leningrad, p. 188 [in Russian].
3. Fletcher TP. Ovatoryctocara granulata: the key to a global Cambrian stage boundary and the correlation of the Olenellid, Redlichiid and Paradoxidid realms. Special Papers in Palaeontology, vol. 70, 2003; p. 73–102.
4. Fletcher TP. The base of Cambrian Series 3: the global significance of key oryctocephalid trilobite ranges in the Kaili formation of South China. Memoir of the association of Australasian palaeontologists, vol. 33, 2007; p. 29–33.
5. Cambrian boundaries and divisions;Robison;Lethaia,1977